Safety device for conveyers.



A. E. HANDY.

SAFETY DEVICE FQR CONVEYERS.

APPLICATION FILED DEC. 12, 1913;

Patented Jan. 4, 1916.

WITNESSES:

W wi

ARTHUR E. HANDY, OF NEW ,YORK, N. Y., ASSIGNOR T OTIS ELEVATOR COMPANY,OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SAFETY DEVICE FOR CONVEYERS.

Specification of Letters Patent.

Patented J an. 4, 1916.

Application m December 12, 1913. Serial in. 806,199.

To all-whom it may concern:

Be it known that I, ARTHUR E. HANDY,

' a citizen of the United States, residing at New York, in the county ofNew York and State of New York, have invented a new and usefulImprovement in Safety Devices for Conveyers, of which the following is aspecification.

freight between different elevations,' and it' is particularly adaptedfor use in conjunction with escalators having an electric power.

unit for driving the sam I I Under abnormal conditions, as for example,upon interruption in the source of power supply, a heavily loadedescalator claims.

will tend to run away, caused by the heavy load thereon, which tends todrive the escalator at an abnormal rate of speed and in a descendingdirection, and oneof the objects of this invention is to provide meansoperable automatically under abnormal conditions for effecting theretardation and final stopping of .the escalator, without subjecting thepassengers to sudden shocks, or jar,

which might tend to throw them in a mannor to cause injury thereto.

Other objects of the invention are as follows: to associate with thesafety device a means operable automaticallyto disconnect the drivingunit from its source of power supply upon each operation of the safetydevice; and to. provide means automatically to prevent the operationofthe escalator in a descending direction unless the safety device is innormal inoperated position.

Still other objects of the invention will appear hereinafter,the novelcombinations of elements being set forth in the appended Referring tothe drawings, Figure 1 shows a fragmentary side elevational view of anescalator with my invention applied thereto; Fig. 2 is a sectional frontelevaoperative connection between the electrotional view of Fig. 1,taken on the line a-a lookin Y My invention is applicable to any of thetypes of inclined conveyors or escalators now commonly used, andtherefore a general description only of the escalator proper will begiven, the type herein shown bein a well know construction, and fullydescribed in in the direction of the arrows b--b..

a patent 1,025,316.

granted to C. 'D. Seeberger, No.

A series of steps 1 are connected by links 2 to forman endless conveyenEach step is provided with an axle bar 3 carrying at each end a yoke 4,provided with bearings for the wheels 5, cooperating with the tracks 6and 7. The links 2associated with the steps mesh with driving sprockets10, driven by a motor M, through a worm and gear connection. .Theelectromagnetic brake apparatus B may be of any well known type, and inthis instance comprises a brake band 11 normally applied by a spring 13to a brake pulley 12, and released therefrom f .upon the ener 'zation ofthe magnet Wind'- ing 14, whic is connected in parallel through theconductors 40 and 40 the shunt terminals of the motor.

A Ssfety device S, is in the form of a shock absorber, and comprises adog 15 keyed to a transverse shaftv 16, suitably journaled in bearings17, formed integrallyv with guide shoes 18, adapted to be guided intheir movement by guide rails 19. The dog 15, as shown in dotted line inFig. 1 is in position to be engaged by the axle 3. An arm 20 formedintegrally with the dog 15 is provided with an adjustable weight 21 Yadapted to rock the dog into-the path of movement of the axles 3, themovement of the dog to this position being limited by a stop 53. Anelectromagnet 22, operatively connected to a lever 23, fixed to theshaft.

16, is adapted to rock the dog 15, out of the path of movement of theaxle 3, as shown in I with full lines in Fig. 1. Heavy coil springs 23are supported by rods 54 suitably secured to plates 55' formedintegrally with each one of the bearings 17. These springs areinterposed between the plates 55 and the abutment 26, and are adapted tobe compressed when the dog is engaged by. the

axle, and thereby retard the movement of the escalator and bring thesame to a final stop. A slot 28 in, the lever 23 permits a movement ofthe dog without disrupting the erates, are moved out of electricalcontact therewith, and the contact 28 carried by:

sa1d switch is moved into electrical engage'-' tacts 34:.

ment with contact 29, the closing of the two latter contacts beingedected before the contacts 24: and 26 are open-circuited, for a purposehereinafter described.

The various other switches, etc., shown in F ig. 1 comprises a manuallyoperated potential switch P, having a self holding winding 30, areversing switch R, adapted to reverse the current through the motor Min a well known manner, an electro-magnet 31. having normally opencontacts 32, and provided with a dashpot 33, and normally open contacts3%, adapted to be close circuited when the electromagnet 22 isenergized. and designate a source of current supply.

The operation will now be described: The various parts as shown in Fig.1, and with the dog in dotted line position, represents the normalpositions thereof, the full line position of the reversing switch B,being for the ascending direction of travel of the escalator, and thedotted line position for descending direction of travel. The main lineswitch is closed manually, and a self holding circuit for the winding30, thereof, is established as follows: through con tacts 35, conductor36, winding 30, contacts 26 and 2d, conductors 52 and 37 to minus line.circuitfor the electromagnet 22 is also established as follows: from thejuno tion 36, conductor 37, electromagnet 22, conduct-or 38, contacts27, and 25, conductors 39,52 and 3? to minus line. The electromagnet 22being energized will now operate and rock the dog out of the path ofmovement of the axles 3, and also clos the con- The switch R is thrownto dotted line position, thereby closing circuits through the armatureof the motor (which is preferably a shunt field motor) shunt field, andwinding is of the lorake magnet; the circuit for the armature being asfollows: -I conductor through contacts 35, conductor 40, through switchto conductor 4:1, contacts 34, conductors 42 and 43, through a rheostatand the armature to conductors n and as, through switch to conductor 16,contacts 48 to minus line. The shunt field circuit is establishedthrough contacts 49 and to the minus line, and the brake circuit acrossthe shunt field in a well known manner. t is to be here noted that inthe operation of the motor to drive the escalator in a descendingdirection, the armature circuit is included through contacts 34., hence,the escalator cannot be started in a descending direction if the safetydevice is operated, but the operation thereof in an ascending directionis permissible. Continuing now with the opera-- tion, the brake willrelease, permitting the motor to run, to eflect the operation of theescalator in a descending direction. Say now, for example, the escalatoris heavily loaded and traveling at a. rate of about 90 or 100 feet perminute, which in practice is about the average rate of speed ofescalators at the present time, and if any abnormal conditions shouldarise, such as the one heretofore recited for example, the potentialswitch will open, the brake will be applied, but is not of sufiicientstrength to stop the escalator under the conditions set forth, and theelectromagnet 22 now being deenergized, the weights21 will now rock thedog 15 into position to be engaged by one of the axles 3, and the heavysprings 23 will now bring the escalator to a gradual stop Without shockor jar to the passengers. The initial operation of the safety deviceefiects the automatic operation of the switch C, toopen-' circuitcontacts 24, 26, and 25 27,.respeotively. The circuit for theelectro-magnet 22 being through contacts 25, and 27, it is thus soonthat said electro-magnet cannot be again. energized until the safetydevice is in normal inoperated position, whereby the switch C is againautomatically returned to normal position, and. consequently theescalator cannot be started in a descending direction, even if througherror the operator tries so to do, until the electro-magnet 22 is againenergized, which will eflect the closing of contacts 34, which arecontained in the motor circuit, for the descending direction of ctravel. of the escalator. To return the safety device to normal positionthe escalator is started in an ascending direction, the poten tialswitch is closed and a circuit is estab lished for the winding of theelectromagnet 31 as follows: conductors 36 and 40, winding 31, conductor51,.contacts 29 and 28, conductors 52 and 37, to minus line. Theelectro-magnet 31 will now close contacts 32, which establish a circuitfor the potential switch, and with the switch R in full line position,the brake will release and the motor will operate the escalator in anascend.- ing direction, and the contacts 28 and 29 will maintain thecircuit of the winding 31, closed, until the switch C is returned tonormal position, the contacts 32 automatically maintaining the potentialswitch circuit therethrough during the movement of the safety device toits normal position, whereafter the contacts 24: and 26 maintain saidcircuit. The escalator having ascended enough to return the safetydevice to normal position, the contacts 25 and 27 being again inelectrical engagement will again close the circuit for theelectro-magnet 22 therethrough, which will operate to rock the dog outof the path of movement of the axles 3.

operation of the escalator in a descending direction after the safetyoperates affords absolute protection against damage to the escalator orsafety device, which would re sult should the operator through oversightstart the escalatorin said direction. Numerous other abnormal conditionsmight arise causing the safety device to operate, upon each operation ofwhich the opening of the potential switch is automatically effected, andin this instance I provide the dashpot 33 to cause a sluggish action ofthe electro-magnet 31, and preventing the closing of contacts 32, whilethe contact 24 is'being moved out of engagement with contact 26, thislapse of time permitting the opening of the potential switch beforethecontacts 32' are closed, but said contacts maintaining a closedcircuit for the winding of the potential switch during the movement ofthe safety device Cto normal position.

It is obvious that various changes can be made in the details ofconstruction and arrangement of parts without departing from the spiritand scope of my invention. I therefore wishnot to be limited to theprecise details of construction and arrangement of parts herein shownand described.

What I claim and desire to protect by Letters Patent of the UnitedStates is z- 1. The combination with an inclined electrically drivenreversible conveyer, an electrically operated bufier device adapted tobe put under pressure by the conveyer for effecting-the retardation ofthe latter when the latter tends to run away, and automatic means forpreventing the operation of the conveyer in a descending directionunless said device is in normalinoperated position.

2. The combination with an inclined electrically driven reversibleconveyer, an electrically operated bufier device adapted to be put underpressure by the conveyer for effecting the retardation of the latterwhen the latter tends torun away, and automatic,

means actuated by said electrically controlled yielding means forpreventing the operation of the conveyer in a descending directionunless said device is in normal inoperated position.

3. The combination with an inclined electrically driven reversibleconveyer, an electrically' operated buffer device adapted to be .putunder pressure by the conveyer for effecting the retardation of thelatter when the latter tends to run away, the circuit to said bufferdevice being automatically broken when the butter device is operated,

thereby preventing the operation of the conveyer in a descendingdirectlon unless said buffer device is in normal noperated position.

4. The combination with an inclined conveyer,'an electrlc power umt fordrlvin the same, a source of current supply there or, a

main line potential switch, electrically controlled yielding means forefiecting the retardation of the conveyer when the latter tends to runaway, and means forautomatically effecting the opening of the potentialswitch simultaneously with the operation of said yielding means.

5. The combination with an inclined -conveyer, an electric power unitfor driving the same, a source of current supply therefor, a main linepotential switch, electrically controlled yielding means for effectingthe retardation of the conveyer when the latter tends to run away, andmeans actuated by said electrically controlled yielding means forautomatically effecting the openingof the potentialswitch simultaneouslywith the Y operation of said yielding means. a l

6. The combination with an inclined re- .versible conveyer, an electricpower unit for driving the same, a source of current supply therefor, amain line potential switch, a re versing switch for said power unit,electrl cally controlled. yielding means for elfecting the retardationof the conveyer when the latter tends to run away, means forautomatically effecting the opening of the potential switchsimultaneously with the operation of the yielding means, and automaticmeans for preventing the operation of the conveyer in a descendingdirection unless said yielding means are in normal position.

7. The combination with an inclined reversible conveyer, an electricpower unit for driving the same, a source of current supply therefor, amain line potential switch, reversing switches for said power unit,electrically controlled yielding means for veffecting the retardation ofthe conveyer when the latter tends to run away, means actuated by saidyleldmg means for automatically effecting the opening of the potentialswitch simultaneously with the operation, of the cally effecting theopening of the potential the operation of l the yielding means, andautomatic means acswitch simultaneouslywit tuatedjby said yieldin'means-for preventmg the operation of t e conve er in a de scendingdirection unless said yielding means are in normal position.

9. The combination with an inclined reversible conveyer, an electricpower unit for driving the same, a source of current supply therefor, amain line potential switch, reversing switches for said power unit,electrically controlled yielding means for effecting the retardation ofthe conveyer when the lat- 'ter tends to run away, means actuated bysaid yielding means for automatically efiecting the opening of thepotential switch simultaneously with the operation of the yieldingmeans, and automatic means actuated by said yielding means forpreventing magma the operation of the conveyer in a descending directionunless said yielding means are in normal position.-

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses.

ARTHUR E. HANDY. Witnesses:

W. H. BRADY, EDGAR W. SMITH.

